A Wilting Sand Cherry Bush

With its showy foliage and tidy growth habit, the purple-leaf sand cherry (Prunus x cistena) makes an attractive and low-maintenance addition to landscaping within U.S. Department of Agriculture plant hardiness zones 2 to 8. It is an adaptable shrub, yet it is susceptible to several illnesses and pests that may cause a wilted appearance. Although most common afflictions are not lethal, they may decrease the shrub's already short lifespan and lessen its ornamental value.

Bacterial and Fungal Infections

Purple-leaf sand cherry is prone to a variety of bacterial and fungal infections, including verticillium wilt, trunk canker, root rot and oak root fungus. The first noticeable symptom of these conditions is wilted foliage, which can be diffuse or localized. Most infections can be prevented by planting the shrub in a suitable location with fast-draining soil and by watering sparingly. Once an infection occurs, the affected branches must be trimmed off and the soil allowed to completely dry out before resuming irrigation. Also, avoid wetting the leaves when watering purple-leaf sand cherry because moisture among the foliage creates ideal conditions for fungal and bacterial growth.

Insect Predators

Insect predators seldom cause permanent damage to established, mature purple-leaf sand cherry shrubs, although they may cause damage to the twigs and foliage. The common culprits are armored scales (Diaspididae spp.) and thrips (Heliothrips haemorrhoidalis), which feed on the foliage and cause a distorted, drooping appearance. Cultural control is best and entails removing old growth and vegetation from around the base of the shrub and providing enough space between the shrubs. Chemical control is seldom effective at eliminating the pests, but a liberal application of neem oil on the foliage may control the insect population in the short term.

Cultural Conditions

Poor cultural conditions such as wet soil and dim light contribute to the wilting and overall decline of purple-leaf sand cherries in two ways. It creates nutrient or mineral deficiencies and poor oxygenation that cause damage such as leaf yellowing and poor branch structure. In this weakened state, the shrub is more susceptible to disease and insect predation. Maintaining an appropriate level of moisture in the soil and keeping the shrub groomed will help preserve its health, which may keep it from developing more serious systemic illness and insect infestations in the future.

Age-related Decline

Purple-leaf sand cherries are short-lived shrubs, with most declining after just 10 years in the garden. Aging shrubs often develop diseases, although they are just as likely to express symptoms of age-related decline. Individual branches will cease to produce new foliage and the current foliage will begin to go limp and fall off. Hard-pruning in spring may invigorate the shrub for a season or two, but it will not prolong its life and may hasten its decline if it is afflicted by pests or disease.

About the Author

Anastasia Leon began writing professionally in 2001. Her experience as a horticulturalist and nurseryman informs her work, which has appeared in publications such as Mother Earth News and Modern Farmer. Leon is a certified master gardener and holds a Bachelor of Arts from the University of California, Santa Cruz.